Detection of extra chromosomes 12 by fluorescent in situ hybridization (FISH) in ovarian stromal tumors. Study of 12 cases and review of the literature

Chromosomic aberrations play a major role in the initiation and the progres sion of benign as well as malignant tumors. In particular, trisomy 12 is fr equently observed in female genitourinary tract tumors and constitutes a re current and often unique anomaly in stromal ovarian tumors such as fibrothe comas. Today, the genetic analysis of fresh or fixed solid tumors is enable d by the fluorescent in situ hybridization method (FISH). Using FISH and/or conventional cytogenetics, we analysed 12 ovarian stromal tumors (6 fibromas, 3 fibrothecomas and 3 thecomas). All of these tumors w ere benign and trisomy 12 was observed in all cases. Moreover, 3 cases pres ented trisomy and tetrasomy for chromosome 12 simultaneously. The high freq uency of trisomy 12 in this tumor type suggests that this abnormality might be implicated in ovarian tumorigenesis.